Core listed as outdated, but composer is not updating it

Question

I'm facing a strange issue with drupal-composer.
It has been installed via the usual command line:

$ composer create-project drupal-composer/drupal-project:8.x-dev ./ --stability dev --no-interaction

Now I want to update drupal/core, and here's what I've got:

$ composer show -l
[...]
drupal/core  8.3.1  8.3.3  Drupal is an open source content management platform powering millions of websites and applications.

$ composer update drupal/core --with-dependencies
> DrupalProject\composer\ScriptHandler::checkComposerVersion
Loading composer repositories with package information
Updating dependencies (including require-dev)
Nothing to install or update
Writing lock file
Generating autoload files
> DrupalProject\composer\ScriptHandler::createRequiredFiles

I've maintained Drupal instances with Composer for monthes, and never faced this kind of issue (other instances have successfully been updated to 8.3.2 or 8.3.3).
I've tried to clear Drupal and Composer caches, and desperately ran /update.php before another try, without luck.

Any thoughts?

Answer 1

Eventually, I fixed this issue running a global:

composer update

Still don't understand what was blocking me from updating drupal/core.

Answer 2

You can use Drush commands to update the drupal code.

drush up